Burner and ignition system

ABSTRACT

A burner assembly including a burner tube having a flamesupporting end and an upstream ignition port which has a scoopshaped baffle associated therewith for emitting a turbulent slip stream of fuel from the burner tube. A pilot is maintained in ignition proximity to the tube ignition port for igniting the slip stream. Upon ignition, the slip stream flame is sucked into the burner tube and delivered to the flame supporting end by the stream of fuel and air flowing through the burner tube. A spark ignitor is mounted near the pilot to light the pilot. A capillary bulb is mounted in heat receiving proximity to the pilot to detect heat of the pilot and control the burner fuel valve so that fuel is not delivered through the burner tube unless the pilot is on.

United States Patent Helke [451 Oct. 29, 1974 BURNER AND IGNITION SYSTEM Primary ExaminerEdward G. Favors [75] Inventor: Robert C. Helke, Walworth, Wis. Attorney Agent or lrm coffee & Sweeney [7 3] Assignee: La Mere magnes a, 57T A 'A'ES'TRXCT' 9 jW A burner assembly including a burner tube having a [22] Filed: Aug. 17, 1973 flame-supporting end and an upstream ignition port which has a scoop-shaped baffle associated therewith [21] Appl' 389l95 for emitting a turbulent slip stream of fuel from the burner tube. A pilot is maintained in ignition proxim- Cl 431/255, 4 1/349 ity to the tube ignition port for igniting the slip stream. [51] Int. Cl. F23q 9/12 Upon ignition, the slip stream flame is sucked into the [53] F e d Of Search 86, 349, 43, 47, 193, burner tube and delivered to the flame supporting end 431/255 by the stream of fuel and air flowing through the burner tube. A spark ignitor is mounted near the pilot [56] References Cited to light the pilot. A capillary bulb. is mounted in heat UNITED STATES PATENTS receiving proximity to the pilot to detect heat of the 2 504 592 4/1950 Scharbau et al. 431/349 x and the burner fuel valve that fuel is #4051999 10/1968 Riehl 431/286 x not delivered through the burner tube unless the Pilot 3,558,938 l/l97l Good 431/255 X is 12 Claims, 6 Drawing Figures MENU-1800129 m4 SHEET 20F 2 Illl'll llllllllllllIlllllL FIG.5

FIG.3

BURNER AND IGNITION SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to improvements in burners and ignition systems. More particularly, the invention relates to burner assemblies which are useful for firing combustion chambers in dry sanitary incinerating toilets.

2. Brief Description of the Prior Art Incinerating toilets of the type fired by fuel burners are well known to the prior art. See for example:

INVENTOR PATENT NO. ISSUED Wood 3,059,597 October 23. I962 La Mere 3.l03,0l7 September l0, I963 Duncan 3,3l9,588 May l6, I967 Frankel 3,323,473 June 6, I967 Frankel 3,338.]9l August 29, I967 SUMMARY OF THE INVENTION The present invention provides a new and useful burner assembly including a burner tube with an ignition port upstream from the flame-supporting outlet. Means associated with the ignition port for causing emission of a small turbulent slip stream of the fuel or fuel-air mixture passing through the burner to the burner exterior through the ignition port. Means are provided adjacent the ignition port for igniting the slip stream and the resultant flame is then drawn into the burner tube through the ignition port and delivered to the flame-supporting outlet of the burner tube.

One form of fuel emission means for association with the burner ignition port is a baffle within the burner tube adjacent the port. In a special form of the device, the baffle is a scoop-shaped indentation in the burner tube wall with the open end of the scoop defining a portion of the periphery of the ignition port at the downstream edge of the baffle.

The ignition system for the burner can be of any known type but in one advantageous form a pilot is maintained near the ignition port for igniting the turbulent slip stream. As a safety precaution, a capillary bulb is mounted in heat receiving proximity to the pilot and the capillary bulb controls the main gas valve so that the gas to the burner tube is not turned on unless the capillary bulb detects the heat of a flame as the pilot. The capillary bulb can be adequately shielded from the heat of the combustion chamber.

While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail a specific embodiment and modification thereof, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment or modification illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of one form of burner assembly of this invention;

FIG. 2 is an end view of the burner of FIG. I with the ignition system shield removed;

FIG. 3 is a view from one side of the burner of FIG. 1;

FIG. 4 is a view from the other side of the burner of FIG. 1;

FIG. 5 is a section along line 5-5 of FIG. I with the ignitor and pilot assembly removed; and

FIG. 6 is a fragmentary perspective view of a burner tube with a modified form of ignition port.

DESCRIPTION OF THE PREFERRED EMBODIMENT The burner assembly illustrated in the drawings is especially adapted for use in a dry sanitary toilet. Many such toilets operate using a burning cycle followed by a cooling cycle. At the initiation of the burning cycle, an electrical signal is given to ready various of the operating components of the toilet. The burner assembly, in the form illustrated, uses that electrical signal to actuate flow of a fuel-air mixture through a burner tube for ignition by a continuously buring pilot. However, flow of fuel is blocked should the pilot be out. w

The burner includes a burner tube 12 having a flameholding or supporting outlet at or adjacent end 12a. The end 12a of burner tube 12 receives a corrugated flame-holder element 14 (FIG. 2) which is secured in position for supporting or holding the burner flame. Upstream from flame holder 14 there is provided an ignition port 16 (FIGS. 1, 2 and 5) and, associated therewith, a baffle 18. In the specific form illustrated the baffle 18 has a scoop-like portion 18a terminating in a reverse rounded edge l8b. Port 16 and baffle 18 can be formed by making an arc-like cut through the burner tube wall defining the edge 18b and then pressing or indenting behind the cut to form scoop 18a as an indentation in the tube wall.

An ignition means is provided for lighting the burner tube. Such ignition means is illustrated in the form of a pilot assembly including pilot tube 20 (FIGS. 1 and 2) mounted in bracket 22 which has an extending leg 22a (FIGS. 2 and 3) spot welded to burner tube 12 to secure pilot tube 20 in proper position. Also aiding in mounting the pilot tube is a pilot tube holding plate 23 (FIGS. 1, 2 and 4) which is secured by a sheet metal screw 24 to bracket 22.

Pilot tube 20 is supplied with fuel through a gas line 25 (FIGS. 1 and 2) and receives air through air intake ports 26. The pilot tube flame-supporting port 28 (FIG. 1) serves not only to ignite the burner tube 12 but also serves as the ignition port for igniting the pilot tube. In the embodiment shown, the pilot is intended to continuously burn.

However, should the pilot become extinguished, for purposes of reigniting the pilot tube there is provided an ignitor assembly in the form of a conventional piezoelectric discharge plur 32 mounted in bracket 34 which in turn has leg 34a (FIG. 2) sopt welded to burner tube 12. An upstanding flange 36 (FIG. 1) is bolted at 38 to bracket 34 and extends upwardly to the discharge plug 32 and assists in retaining the discharge plug in proper position. Discharge plug 32 has an electrode 40 which extends (FIG. 1) to a position adjacent the pilot port 28. Pilot tube 20 is grounded and, responsive to manually applied pressure on the piezoelectric element of plug 32, electrode 40 discharges a spark toward the pilot tube for igniting the pilot at port 28.

As a safety measure, a flame-sensing system is also provided to turn off the gas to the burner tube 12 should the pilot become extinguished. Accordingly, a capillary bulb 44 (FIG. 1) is mounted adjacent and in heat receiving proximity to pilot port 28 on bracket 22 by a spring clip 46. A pressure transmitting tube 48 extends from bulb 44 to a pressure sensitive control, shown schematically at 50, for closing and opening the main gas valve associated with control 50. Pressure build-up within the capillary bulb 44, as a result of the pilot flame, permits the main gas valve to open if all other necessary conditions are met, e.g., if the toilet seat is down and the burning cycle has been initiated. Should the pilot be extinguished at the time the ignition signal is received by the main gas valve, as at 50, the capillary bulb senses this condition as a low pressure condition and causes the gas valve control 50 to block the gas valve from opening. The discharge plug is then manipulated to light pilot port 28 or a match or the like is used.

A shield 54 is also provided surrounding the burner tube at about the position of the corrugated flame holder 14. Shield 54 completely protects the pilot and ignition systems from exhaust gages, back drafts, stream, and the like as found in the normal incineration of waste products.

In operation of the device, with the pilot burning when the ignition signal is received the capillary 44 is up to temperature and control 50 permits the main gas valve to open. A gas-air mixture is supplied through tube 12 toward flame-supporting outlet 12a. As the gas-air mixture reaches port 16 and baffle 18, immediately behind the corrugated flame holder 14, a small amount of the mixture is expelled through port 16 into the ignition area of the pilot flame at 28. This gas and air mixture is ignitied by the pilot and travels down through the small port 16, through the corrugated flame holder 14 and to the downstream side of flame holder 14 where the flame is held by holder 14 in a conventional manner.

The flow of fuel from the port 16 is apparently aided by the inside diameter of tube 12, the restriction provided by corrugated flame holder 14 and/or the baffle 18 which extends into port 16.

The size of the ignition port 16 can be changed to obtain greater or lesser emission of the air and gas mixture from tube 12 for ignition purposes. For example, a modification illustrated by FIG. 6 employs an ignition port in the form of a small bore 116 in a forward wall 1180 of an indentation forming a scoop-like baffle portion 118a. Wall 1180 joins baffle 118a at contiguous corner ll8b. This arrangement provides a smaller ignition port and a lower rate of slip-stream emission during ignition. Other modifications will be apparent to those in the art.

I claim:

1. A burner assembly comprisng a burner tube having a flame-supporting outlet, an ignition port in said tube upstream from said flame-supporting outlet, baffle means associated with said ignition port and extending into the burner tube at said ignition port for emitting a small turbulent portion of the fluid fuel passing through said burner tube from said ignition port, said baffle means being a scoop-shaped indentation in the burner tube wall with the open end of the scoop defining a portion of the periphery of the ignition port and defining the downstream edge of the baffle in the form of a reverse rounded edge, and ignition means for igniting the emitted-turbulent portion whereby said fuel within the burner tube is also ignited and the flame travels from said ignition port through the burner tube to said flamesupporting outlet.

2. A burner assembly comprising a burner tube having a flame-supporting outlet, an ignition port in said tube upstream from said flame-supporting outlet, means associated with said ignition port for emitting a small turbulent portion of the fluid fuel passing through said burner tube from said ignition port to the exterior of said burner tube, and ignition means for igniting the emitted turbulent portion whereby the ignited turbulent portion is drawn into the burner tube to ignite fluid fuel within the burner tube and the resulting flame within the burner tube travels from said ignition port through the burner tube to said flame-supporting outlet.

3. The assembly of claim 2 wherein said emitting means comprises baffle means extending into the burner tube at said ignition port.

4. The assembly of claim 3 wherein the baffle means is a scoop shaped indentation in the burner tube wall with the open end of the scoop defining a portion of the periphery of the ignition port and defining the downstream edge of the baffle.

5. The assembly of claim 2 wherein said emitting means is an indentation in the burner tube wall having upstream and downstream wall portions and said ignition'port is located in the downstream wall.

6. The assembly of claim 2 wherein said ignition means comprises a pilot having a flame-supporting port adjacent said ignition port.

7. The assembly of claim 6 including a capillary bulb in heat receiving proximity to said pilot flamesupporting port for detecting flame at said port.

8. The assembly of claim 7 including a pressure responsive fuel valve control for controlling flow of fuel to said burner tube and conduit means communicating said capillary bulb with said fuel valve control for blocking opening of said fuel valve responsive to a decrease in pressure within said bulb determinitive of a noflame condition at said pilot port.

9. The assembly of claim 6 including manually operable ignition means adjacent said pilot port for igniting the pilot.

10. The assembly of claim 9 wherein said ignition means is a discharge plug having a pressure responsive piezoelectric element for generating an electric spark.

11. The assembly of claim 2 including a capillary bulb means adjacent said ignition means for detecting heat from said ignition means and valve means responsive to detection of heat by said bulb means for admitting fuel to said burner tube.

12. The assembly of claim 11 including shield means for shielding said capillary bulb from the burner tube flame.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,844,704 Dated October 29, 1974 Inventor(s) Robert C. Helke It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 65, "plur" should be "plug"; Column 2, line 66, "sopt" should be "spot"; Column 3, line 32, "gages" should be "gases"; and Column 3, line 33, "stream" should be "steam" Signs- 3 and sealed this lst day of April 1975.

(SEAL r kt t es 1: I n

C IIARSHALL DANN RUTH C. l-iASON Commissioner of Patents Attesting, Officer and Trademarks FORM PO-1050 (10-69) USCOMM-DC BOS'IO-PGQ R ".5. GOVERNMENT PRINTING OFFICE I9. O-Jll-SSI, 

1. A burner assembly comprisng a burner tube having a flamesupporting outlet, an ignition port in said tube upstream from said flame-supporting outlet, baffle means associated with said ignition port and extending into the burner tube at said ignition port for emitting a small turbulent portion of the fluid fuel passing through said burner tube from said ignition port, said baffle means being a scoop-shaped indentation in the burner tube wall with the open end of the scoop defining a portion of the periphery of the ignition port and defining the downstream edge of the baffle in the form of a reverse rounded edge, and ignition means for igniting the emitted turbulent portion whereby said fuel within the burner tube is also ignited and the flame travels from said ignition port through the burner tube to said flamesupporting outlet.
 2. A burner assembly comprising a burner tube having a flame-supporting outlet, an ignition port in said tube upstream from said flame-supporting outlet, means associated with said ignition port for emitting a small turbulent portion of the fluid fuel passing through said burner tube from said ignition port to the exterior of said burner tube, and ignition means for igniting the emitted turbulent portion whereby the ignited turbulent portion is drawn into the burner tube to ignite fluid fuel within the burner tube and the resulting flame within the burner tube travels from said ignition port through the burner tube to said flame-supporting outlet.
 3. The assembly of claim 2 wherein said emitting means comprises baffle means extending into the burner tube at said ignition port.
 4. The assembly of claim 3 wherein the baffle means is a scoop shaped indentation in the burner tube wall with the open end of the scoop defining a portion of the periphery of the ignition port and defining the downstream edge of the baffle.
 5. The assembly of claim 2 wherein said emitting means is an indentation in the burner tube wall having upstream and downstream wall portions and said ignition port is located in the downstream wall.
 6. The assembly of claim 2 wherein said ignition means comprises a pilot having a flame-supporting port adjacent said ignition port.
 7. The assembly of claim 6 including a capillary bulb in heat receiving proximity to said pilot flame-supporting port for detecting flame at said port.
 8. The assembly of claim 7 including a pressure responsive fuel valve control for controlling flow of fuel to said burner tube and conduit means communicating said capillary bulb with said fuel valve control for blocking opening of said fuel valve responsive to a decrease in pressure within said bulb determinitive of a no-flame condition at said pilot port.
 9. The assembly of claim 6 including manually operable ignition means adjacent said pilot port for igniting the pilot.
 10. The assembly of claim 9 wherein said ignition means is a discharge plug having a pressure responsive piezoelectric element for generating an electric spark.
 11. The assembly of claim 2 including a capillary bulb means adjacent said ignition means for detecting heat from said ignition means and valve means responsive to detection of heat by said bulb means for admitting fuel to said burner tube.
 12. The assembly of claim 11 including shield means for shielding said capillary bulb from the burner tube flame. 